Wear and Mechanical Properties of Aluminum Alloy Based Hybrid Composites [(SiC+Gr) and (SiC+Al₂O₃)] Fabricated by Friction Stir Processing

In this investigation, the influence of tool rotational speed on wear and mechanical properties of Aluminum alloy based surface hybrid composites fabricated via Friction stir processing (FSP) was studied. The fabricated surface hybrid composites have been examined by optical microscope for dispersion of reinforcement particles. Microstructures of all the surface hybrid composites revealed that the reinforcement particles (SiC, Gr and Al₂O₃) are uniformly dispersed in the nugget zone. It is observed that the microhardness is decreased with increasing the rotational speed and exhibited higher microhardness value in Al-SiC/Al₂O₃ surface hybrid composite at a rotational speed of 900 rpm, due to presence and pining effect of hard SiC and Al₂O₃ particles. It is also observed that high wear resistance exhibited in the Al-SiC/Gr surface hybrid composites at a rotational speed of 900 rpm due to presence of SiC and Gr acted as load bearing elements and solid lubricant respectively. The observed wear and mechanical properties have been correlated with microstructures and worn morphology.